Air shutter for gas burners



May 6, 1947. P. s. HARPER 2,419,995

AIR SHUTTER FOR GAS BURNERS Filed Marci: 24, 1945 F1 7 I 69 J\ E o o A 921. o o

INVENTOR.

Patented May 6, 1947 AIR SHUTTER FOR GAS BURNERS Philip S. Harper, Chicago, Ill., assignor of onefourth to Philip S. Harper and one-fourth to Carolyn L. Harper, both of Chicago, Ill., and one-fourth to Harris Trust and Savings Bank, an Illinois banking corporation, as trustee of the Philip S. Harper Trust, and one-fourth to said Harris Trust and Savings Bank, as trustee of the Carolyn L. Harper Trust Application March 24, 1945, Serial No. 584,705

9 Claims. (Cl. 158-118) The present invention relates to air shutters for gas burners and the like.

Among the objects of the present invention is to provide novel shutter mechanism for adjusting the air intake into a mixer tube or the like for a gas burner which can be readily and easily manipulated from the top of the mixer tube even While the burner is in operation.

Another object of the present invention is to provide shutter mechanism which is of simple construction, which can be manufactured and installed at relatively low cost, and which requires a minimum of machine work on the mixer tube castings on which the same is mounted.

The invention has as a further object the idea of providing readily manipulatable air shutter mechanism for double burner mixer tubes which will eliminate any possibility of flash-back to either of the orifices being propagated to the other.

Still another object of the present invention is to provide novel shutter mechanism for double burner mixer tubes, one 7 of which shutters is mounted on the top of the mixer tube for controlling air intake through an opening into one of the ducts of the tube, the other shutter of which is mounted on the bottom for controlling air intake through an opening communicating with another duct in the tube, and both of which shutters are readily and easily adjusted in various positions from the top of the mixer tube.

Other objects, features, capabilities and advantages are comprehended by the invention, as will later appear and as are inherently possessed thereby.

Referring now to the drawings- Figure 1 is a top plan viewof a gas burner assembly incorporating shutter mechanism for control of air intake into the burner which is made in accordance with the present invention;

Figure 2 is a fragmentary view in side elevation of the device shown in Figure l. of the drawmgs;

Figure 3 is a view in end elevation of the structure shown in Figure 1 of the drawings;

Figure 4 is a fragmentary bottom plan view of the structure shown in Figure l of the drawings; Figure 5 is a fragmentary bottom plan view of a modified form of construction; and

Figure 6 is a View in end elevation of the modified structure shown in Figure 5 of the drawings.

Referring now more in detail to thedrawings, shutter mechanism made in accordance with the present invention is shown in Figure 1 of the drawings as being associated with a mixer tube 4 adapted to supply a combustible air-gas mixture to a centrally disposed simmer burner 5 and an annular shaped main burner 1 spaced therefrom. Extending between the simmer burner 5' and a lighter cup 9 is a flash tube 8 whereby lighting of the simmer burner 5 may be effected from a pilotlight H.

The simmer and mainburners are formed with chambers and ports, the simmer chamber communicating with the duct l4 formed in the mixer tube 4 and the main burner communicating with the duct l6 of the mixer tube 4 through a lateral passage formedin the extension l3 which provides a base for mounting the main burner on the mixer tube 4. Duct l4 communicates at the end of the mixer tube 4 with an opening l8 constituting means for introducing air into the duct M where the same is mixed in proper proportions with gas introduced through the opening IE to form a combustible air-gas mixture for the simmer burner 5. Duct It communicates with an opening 2!! formed in the bottom of the mixer tube-casting and which opening serves as an intake for air in suitable proportions for mixture with gas introduced through the opening ll to form a combustible air-gas mixture for the main burner l.

The shutter mechanism according to the present invention is particularly adapted for simplifiecl manufacturing procedures leading to low cost in the elements forming the same as well as minimizing machining costs in forming the mixer tube 4. Such shutter mechanism involves an upper shutter element 22 slidably mounted on the top of the mixer tube for adjusting the air intake through the openings l8. Such mechanism further includes the shutter element 24 mounted in slidable and engageable relation to the mixer tube at thebottom thereof and which is adjustable for varying the air intake through the opening 20. Such shutter elements are positioned with respect to the mixer tube through the medium of the cross bars 26 and 28, the former being associated with the shutter element 2'2 and th latter being associated with the shutter element 24.

The entire assembly is held in adjusted position and readily adjusted when necessary through the medium of bolts 39 and 32, the bolt 30 passing downwardly through openings in the cross bar 26 and shutter element 22 and through an opening provided in the ofi-set 3 in the mixer tube casting. Bolt 36 is slotted at its upper end and has threaded engagement with the cross bar 28. Bolt 32 is similarly'mounted with respect to the mixer tube casting and shutter elements 22 and 24 ex- 3 cent that this bolt passes through an opening in the shutter element 24. Thus, by virtue of the bolts 30 and 32 and their mounting with respect to the mixer tube casting and shutter elements 22 and '24, such shutter elements are pivotally mounted for movement about the bolts and may be readily unlocked for adjustment or secured in any desired position by the application of a tool to the slotted heads of the bolt and manipulation of the tool to effect the desired adjustment of such bolts.

The shutter elements 22 and 24 are of identical construction, each being formed with an ear 36 extending outwardly beyond the pivot point for the shutter element whereby the shutter element may be readily adjusted about its pivot point at any time. Such shutter elements are further formed with the laterally extending lugs 38 and 49 engageable with the adjacent cross bar for limiting the movement of the shutter elements; 7

With the construction as above described, ample openings are provided for proper primary air injection into the ducts l4 and IS and at the same tim an assembly is provided which is easily and readily manipulated from the top of the mixer tube casting, even though the burners are operating. This facilitates proper adjustment for the most efficient operation of the burner, thus leading to economies in that respect. Furthermore, inasmuch as the openings are provided on the top and bottom of the mixer tube casting, the possibility of flashback to either of the orifices being propagated to the other is eliminated.

The present invention also contemplates a novel adjustable shutter mechanism conforming in a good many respects to that above described, yet which is adapted for. use in connection with a single burnera Figures and 6 are representative of such structure, the same disclosing a shutter mechanism 42 associated with a mixer tube 44 having a single duct 46 adapted to supply a combustible air-gas mixture to a single burner. This duct 46 communicates with an opening 48 formed in the bottom of the mixer tube casting and which opening is regulated by the shutter element 50 disposed in sliding relation to the bottom machined surface of the mixer tube casting. This shutter element is secured in adjusted relation to the openin 48 through the medium of the two bolts 52 and 54 extending down through suitable openings provided in the lateral extensions 56 and 58 of the mixer tube casting, such bolts being threaded at their lower ends adapted to threadedly engage a cross bar 60 extending across the shutter element 50. As in the first described embodiment, the bolts' 52 and 54 are slotted across the heads thereof for reception of a tool which when suitably manipulated is adapted to loosen or tighten the cross bar 60 with respect to the shutter element 50 whereby the same can be adjusted and locked in any of said adjusted positions. The shutter element 50 is further formed with an ear 62 whereby manipulation thereof can be efiected from the top. of the mixer tube casting. Furthermore, shutter element 50 is formed with the laterally extending lugs 64 and 66 engageable withthe cross bar 60 for limiting its rotary movement about the bolt 54.

All of the advantages inherently characterizing the embodiment disclosed in Figures 1-3 are possessed by the modified construction showing the adaptation of the invention to-a single burner.

4 While I have herein described and upon the drawings shown an illustrative embodiment of the invention, it is to be understood that the invention is not limited thereto but may'comprehend other constructions, arrangements of parts,

. details and features without departing from the spirit of the invention.

What is claimed is:

1. In a mixer tube for gas burners and the like, the combination of a duct in said tube having an atmospheric opening in the bottom of the tube, an air shutter for said opening for varying the air intake into said tube, means for adjustably securing said shutter with respect to said opening comprising a pair of bolts manipulatable from the top of said tube and disposed within openings provided therein, said shutter being pivotally secured to one of said bolts, a cross bar extending across said shutter and having threaded relation at its ends with the bolts respectively, and spaced lugs provided on said shutter and being engageable with said cross bar for limiting rotation of said shutter.

2. In a mixer tube for gas burners and the like, the combination of a duct in said tube hav in an atmospheric opening in the bottom of the tube, an air shutter for said opening for varying the air intake into said tube, means for adjustably securing said shutter with respect to said opening comprising a pair of bolts manipulatable from the top of said tube and disposed within openings provided therein, said shutter being pivotall secured to one of said bolts, a cross bar engageable with said shutter and having threaded relation at its ends with said bolts respectively, and said shutter having an ear extending outwardly beyond the pivot axis for facilitating adjustment of the shutter from the top of said tube.

3. In a mixer tube for gas burners and the like, the combination of a pair of ducts one of which has an opening in the bottom of said tube and the other of which has an. opening .in the top,o f said tube, an air shutter for the top opening an air shutter for the bottom opening forwarye ing the air intake into said ducts respectively, and means for adjustably securing said shutters with respect to said openings comprising a cross bar engageable with each of said shutters, and

a pair of bolts manipulatable from the top of said tube passing downwardly through said top cross bar and openings provided in said tube and having threaded engagement with said bottom cross bar. 1 1

4; An adjustable shutter mechanism according to claim 3, wherein said shutters are pivotally mounted on said bolts. z

5. An adjustable shutter mechanism according to claim 3, wherein one of said shutters is pivote ally mounted on one of said bolts and the other of said shutters is pivotally mounted on the other of said bolts. i 1 6. An adjustable shutter mechanism according to claim 3, wherein one of said shutters is'plvotally mounted on one of said bolts and the other of said shutters is pivotally mounted on the other of said'bolts and the shutters are provided with lugs engageable with the cross bars for limiting rotation thereof relative to the tube;

7. An adjustable shutter mechanism according to claim 3, wherein one of said shutters is pivot ears for ease of adjustment from the top of the tube REFERENCES CITED An adjustable shutter mechanism according The following references are of record in the to claim 3, wherein one of said shutters is pivotfil f this patent; ally mounted on one of said bolts and the other of said shutters is pivotally mounted on the other UNITED STATES PATENTS of said bolts, and the shutters are provided with Number Name Date lugs engageable with the cross bar-s for limiting 1,134,863 Johnston Apr. 6, 1915 rotation thereof relative to the tube and with ears 1,919,894 Lorimer July 25, 1933 for ease of adjustment from the top of the tube. to 1,968,203 Harper July 31, 1934 9. An adjustable shutter mechanism according 2,300,961 Pratt Nov. 3, 1942 to claim 3, wherein the top and bottom shutters are of identical construction.

PHILIP S. HARPER. 

